Tape control for projectors



Aug- 7 1934- R. F. yDIRKES Er Al. 1,969,297

TAPE CONTROL FOR PROJEGTORS 2 Sheets-Sheet l Filed Dec. 2, 1950gnou/dois: R. F. DIRKES G. LROBERT'Sv All@ 7, 1934- R. F. DlRKEs Er ALTAPE CONTROL FOR PROJECTORS Sheets-Sheet 2 Filed Dec. 2, 1930 53 f um/55 jwvenozs:

R. F. DIRKES G, I ROBERTS wmfffm l 1 n ll Patented Aug. 7, 1934 UNITEDSTATES PATENT oFFicE TAPE CONTROL FOR PROJECTORS Application December 2,1930, Serial No. 499,588

14 Claims.

'Ihis invention relates to a telegraph printing and projecting system inwhich information printed upon a tape is projected upon a screen forobservation. More particularly the invention relates to means forcontrolling the feeding of the tape through the projector so that theprojected images will advance across the Screen with an even movement sothat they may be easily discerned.

v Several projection systems are in general use in connection with stockor news items, the ticker printing the quotations or other items ofinformation upon a specially prepared tape from which they are projectedonto a screen for simultaneous observation by a large number of persons.

In order to eliminate a jerky motion of the projected image, it is thepractice to employ a tape puller operated by an electric motor, whichdraws the tape through the projector in a continuous movement atsubstantially the speed at which the tape is ejected from the ticker. Alight leaf spring bears on the tape so that a loop is formed between theticker and the projector to absorb the jerky motion by which the tape isfed out of the ticker. A switch lever having its free end resting in theloop controls the operation of the tape puller, either through contactsin the motor circuit or through a clutch intermediate the motor shaftand the tape puller, or in some other suitable manner. One of thesearrangements is disclosed in a patent to R. F. Dirkes, Serial No.1,684,309.

At certain relative speeds of operation of the ticker and of the tapepuller, however, the switch lever may take a critical position withrelation to its contacts, so that the tape puller starts and stops foreach character printed, thereby producing a jerky image on the screen.

One of the objects of the present invention is to provide a control forthe tape puller which is not subject ,to this condition and which, whenoperation of the tape puller is once started, will cause it to continueto operate until at least a predetermined plural number of charactershave progressed through the projector.

Other objects and advantages of the invention will hereinafter appear;

In accordance with one embodiment of our invention, we operate the tapepuller by a continuously running motor through a clutch, and disengagethe clutch by means of a magnet or other electromagnetic device to stopthe operation of the tape puller. The circuit of the magnet is eitheropened or closed to effect engagement of the clutch whenever a loop ofsufficient size has accumulated. When the circuit has been conditionedso as to start the tape moving through the projector, it cannot bealtered, to disengage the clutch, until the loop has decreased to asize, below that at which it caused engage ment -of the clutch,equivalent to a predetermined number of characters, which forconvenience may be ve or six. Conversely, once the tape pullerhas beenstopped, it cannot be started again until the loop increases in lengthan amount equivalent to said predetermined number of characters.

A number of different Ways of obtaining this lag between the startingand stopping of the tape puller may be devised, several of which aredisclosed in the accompanying drawings, which will now be referred tofor a more complete understanding of the invention, and wherein:

Figure 1 is a diagrammatic view showing the relation of the ticker andprojector and embodying the present invention;

Figure 2 is a partially diagrammatic perspective view of the embodimentshown in Figure l;

Figure 3 is a side elevation of a modification of the invention;

Figure 4 is a plan view of the form shown in Figure 3;

Figure 5 is a side elevation of a further modication;

Figure 6 is a plan view of the form shown in Figure 5; and

Figure '7 is a diagrammatic view showing the control applied directly tothe motor circuit.

Referring rst to Figure 1, the tape which is contained upon a reel'lo,is fed through a ticker or other printing telegraph apparatusrepresented conventionally by the type wheel 11, platen 12, and feedrollers 13, by the latter of which the tape is intermittently steppedforward, as each character is printed thereon. Ob- Viously, any type oftape printer may be employed, operated either by a uniform code or bystep-by-step signals.

The tape is drawn across the support or platform 14 of the tapeprojector, the details of iio lever 17 having one end 18 extendingacross the loop and the opposite end pivoted at 19.

The tape feeding device or puller 15 comprises a continuously operatingelectric motor 20, the shaft 21 thereof having a clutch member 22splined thereon and movable longitudinally by means of a yoke arm 23carried by a rock shaft 24. A worm gear 25 carrying a driven clutchmember 26 at one end and a ratchet wheel 27 at the other end, is looseon the shaft. A stop arm 28 carried by the yoke arm 23, engages theratchet wheel 27 when the clutch members 22 and 26 are disengaged, tostop the worm gear and lock it against movement. The worm 25 meshes witha gear 29 on the shaft 30, which carries the tape pulling roller 31. Aspring pressed idler roller 32 cooperates with the roller 31 to grip thetape.

The rock shaft 24 carries an armature 33 which is attracted by a magnet34, when energized, to engage the clutch members 22 and 26 and disengagethe stop arm 28, the parts being returned by a spring 35 when the magnetis de-energized.

The lever 17 is grounded and plays betweenA two contacts 36 and 37connected respectively to one terminal of the windings 38 and 39 of arelay 40. The opposite terminals of the windings have a source ofpotential applied thereto. The armature of the relay is also groundedand engages contacts 41 or 42 respectively, when the winding 38 or 39 isenergized. The relay may be of any suitable construction in which therelay tongue is biased against either of its contacts, after being movedthereto, until it is positively moved'to vthe other contact byenergizing of the opposite winding. This characteristic of the relay isrepresented diagrammatically by the toggle spring 43. Contact 41 is idleand contact 42 is connected to the winding of the magnet 34.

When the loop 16 is of at least a predetermined size,'the lever 17 restsagainst its lower contact, thus completing a circuit to hold the relaytongue against its contact 42, whereby the magnet is energized and theclutch 22 engaged.

The motor speed is regulated so that when the stock quotations followeach other in rapid succession, which is the normal condition, the tapeis moved continuously and smoothly without any fluctuations. When theticker slows down below the speed of the tape puller, for an interval,the loop 16 gradually decreases, rocking the lever 17 upward until itengages its upper contact 36, thereby completing a circuit to move therelay tongue against its idle contact 41 and interrupt ing the magnetcircuit. The clutch 22 is thus disengaged by the spring 35 and the tapefeed rollers 31 is brought to rest.

Due to the biasing of the relay tongue in either set position, the tapefeed roller 31 remains idle,- once it has stopped, until the lever 17drops into engagement with the contact 37. The spacing of these contactsis such that there will be an increase in the length of the loop betweenclosing of the contacts 36 and 37 sufficient to provide for apredetermined number of characters, as for instance six.` Consequentlyafter the tape feed roller, stops it will not be started again untilafter this number of characters has been printed and having oncestarted, it will not stop again until the tape has been advanced throughthe projecting apparatus a distance equal to at least this predeterminednumber of characters.

It will be appreciated that under normal conditions with the tape pulleroperating only slightly faster than the ticker, a considerable periodwill elapse after the tape puller starts t0 operate, before it will gainon the ticker, six complete characters and during such periods theprojected images will move evenly and smoothly across the screen.

In Figure 3 we have shown an arrangement in which a mechanical toggle isoperated by the tape control lever in place of the biased relay. In thisform the lever 17 is rigidly secured to a stub shaft 45 mounted in abearing 46 carried by the frame member 47. A downwardly extending togglearm 48 is rigidly secured to the op.- posite end of the shaft 45 torocktherewith, and a switch lever 49 is loosely mounted on the shaft andarranged to play between spaced contacts 50 and 51. A toggle spring 52connects the switch larm 49 and the arm 48 at opposite sides of thepivot point.

With the tape lever 17 in the lower position the toggle arm 48 is swungto the left of the pivot point with the spring 52 in position to holdtheswitch arm 49 on its contact 50 and thereby to complete a circuit forthe clutch magnet 34 so as to effect engagement of the clutch members 22and 26. As the loop shortens the toggle arm 48 is rocked to the right ofits pivot 100 point until the spring 52 passes the dead center,whereupon switch lever '49 is toggled over to its dead contact 51,thereby opening the magnet circuit, to stop the tape feed.

In Figures 5 and 6 the tape is drawn through 105 `the projectingapparatus by an electric motor and frictiongclutch, not shown, themotion of the tape being arrested by the gripping action of a roller 53and a cooperating fixed roller 54. Roller 53 is carried on a shaft 55extending from 110 the frame member 47 and roller 54 is rigidly mountedupon. an arm 56 pivoted on the shaft 57. It is urged toward the roller53 into contact with the tape, by a coiled spring 58 and is adapted tobe held out of contact with the tape by an electro-magnet 59. The tapelever 60 is also mounted on the shaft 57 and plays between upper andlower contacts 6l and 62 respectively, which control the opera/tion ofthe biased relay 40, to energize the magnet 59, when a loop of tape ofpredetermined size forms, thereby separating the rollers 53 and 54 topermit the tape to be drawn through the .projector by the frictionclutch. In Figure 5 the lever 60 is shown approaching its lowercontaotjust prior to disenl gaging the gripping rollers 53 and 54. After thetape has started and the loop decreased sufficiently to raise the lever60 into engagement with contact 61, relay 40 operates to the oppositeside, de-energizing the magnet 59 and permitting the 130 roller 54 to belifted into engagement with the roller 53, to stop the tape.

In Figure 7 the tape feed roller 31 is mounted directly on the shaft 63,of the motor 64 and starting and stopping thereof is effected by closingland opening the motor circuit. In this embodiment the relay 40 closesthe motor circuit when the loop attains a predetermined length and opensthe motor circuit only after the loop decreases to a predeterminedlesser length.

Obviously various other modifications and arrangements, embodying theinvention, will occur to those skilled in the art and, therefore, we donot desire fto be limited to the details shown and described, except inaccordance with the ap- 145 pended claims.

What we claim is:

1. In combination, a tape support, tape printing telegraph apparatus,means' for maintaining 'the tape taut across the support, means formain- 150 taining a predetermined slack in the tape between saidprinting apparatus and support, comprising a switch arm having spacedlimits of movement, means for drawing said tape at an even pace acrosssaid support, means actuated only when the switch arm reaches one limitof movement for arresting the motion of the tape and means formaintaining said tape at rest until the switch arm reaches its otherlimit of movement.

2. In combination, tape printing telegraph apparatus adapted to producea supply of printed tape, means for maintaining the tape taut across apredetermined space, means for producing a loop in the tape between saidprinting apparatus and said predetermined space comprising a switch armriding in said loop and having upper and lower contacts, means fordrawing said tape at an even pace across said space, circuit meanscompleted when said switch arm comes into engagement with its uppercontact for arresting the motion of the tape and means'for maintainingsaid tape at rest until said switch arm engages its lower contact.

3. In combination, a tape support, tape printing telegraph apparatus,means for maintaining the tape taut across the support, means forproducing a loop in the tape between said support and printing apparatuscomprising an arm riding in the loop and having upper and lower limitsof movement, .means for drawing said tape at an even pace across saidsupport, a two-position switch means biased to each set position andmeans controlled by said switch for arresting the motion of said tapewhen said arm is in its upper limit of movement and for maintaining saidtape at rest until the arm reaches its lower limit of movement.

4. In combination, tape printing telegraph apparatus adapted to producea supply of printed tape, means for maintaining the printed tape tautacross a predetermined space, means for producing a loop in the tapebetween said predetermined space and the printing apparatus comprisingan arm riding in said loop and having upper and lower limits ofmovement, corresponding to an increase in the length of the loop ofseveral characters, means for passing the tape across said space, meansfor stopping the tape, said last means initiated into operation onlywhen said arm is in its upper limit of movement and means for againstarting the tape only when said arm reaches its lower limit ofmovement.

5. In combination, a tape support, tape printing telegraph apparatus,means for maintaining the tape taut across the support, means formaintaining a predetermined slack in the tape between said support andthe printing apparatus comprising a switch arm having two contactsspaced apart a distance corresponding to a change in the length of theloop of several characters, means for passing the tape across saidsupport, a relay operated to opposite positions when said switch armengages its opposite contacts respectively, means for maintaining saidrelay in each set position when said switch arm is intermediate itscontacts and electrically operated means, controlled by said relay, inone position for stopping the movement of said tape across the supportand in the other position for starting the movement of the tape acrossthe support.

6. In combination. tape printing telegraph apparatus adapted to producea supply of printed tape, means 'for maintaining the printed tape tautacross a predetermined space, means for maintaining a predeterminedslack in the tape between said predetermined space and the printingapparatus, comprising a switch arm having two contacts spaced apart adistance corresponding to a change in the length of the loop of severalcharacters', means for passing the tape across said space, comprising acontinuously running motor', a feed roller, a clutch intermediate saidmotor and feed roller, a relay operated to opposite positions when saidswitch arm engages its opposite contacts respectively, means formaintaining said relay in each set position when said switch arm isintermediate its contacts and means, controlled by said relay, in oneposition for disengaging said clutch and in the other position forengaging the clutch.

'7. In combination, tape printing telegraph apparatus adapted to producea supply of printed tape, means for maintaining the printed tape tautacross a predetermined space, means for maintaining a predeterminedslack in the tape between said predetermined space and the printingapparatus, comprising a switch arm having two contacts spaced apart adistance corresponding to a change in the length of the loop of severalcharacters, means for passing the tape across said space, comprising acontinuously running motor, a feed roller driven thereby, a relayoperated to opposite positions when said switch arm engages its oppositecontacts respectively, means for maintaining said relay in each setposition when said switch arm is intermediate its contacts and means,controlled by said relay, in one position for driving said feed rollerfrom said motor and in the other position for stopping the feed roller.

8. In combination, tape printing telegraph apparatus adapted to producea supply of printed tape, means for maintaining the tape taut across a,predetermined space, means for producing a loop in the tape between saidprinting apparatus and said predetermined space, comprising an armriding in said loop and having upper and lower limits of movement, anelectric motor for drawing the tape at an even pace across said space, acircuit therefor, means for interrupting said circuit only when saidlever is in its upper limit of movement and for again closing saidcircuit only when said lever reaches its lower limit of movement.

9. In combination, a data recording device, a tape support, means forfeeding tape over said support, and a two-position switch elementcontrolled by said tape adapted to start and stop said feeding means inaccordance with the amount of tape between said data recording deviceand support, said switch element on being operated to one position tostop the feeding means, retaining said position until a predeterminedplural number of characters have been printed by said data recordingdevice and, upon being operated to the other position to start thefeeding means, remaining in said last position until a-length of tapecorresponding to at least said predetermined plural number ofcharacters, has been advanced along said support.

10. In combination, a web, a data recording device for said web, meansfor feeding said web across a predetermined space, a toggle switchhaving two closed positions and being controlled by said web, saidswitch in one closed position controlling the starting of the web and inthe other closed position serving to determine the stopping of said webin accordance with the length thereof between the recording device andsaid space and also serving to maintain the web at rest until apredetermined greater length of tape corresponding to a plural number ofcharacters has formed between the recording device and saidpredetermined space.

11. In combination, a web, a data recording device for said web, meansfor feeding said web across a predetermined space, a two position toggleswitch having two closed positions and being controlled by said web inaccordance with the length thereof between the recording device and saidspace, said switch in one position controlling the stopping of the weband in the other position controlling the starting thereof.

12. In combination a web, a data. recording device for said web, meansfor feeding said web across a predetermined space, an electromechanically operated switch having two closed po sitions and beingadapted to retain each set position until actuated completely to theother position, means controlled by the length of tape between therecording device and said space for actuating said switch in oneposition thereof for stopping the web and in the other position thereoffor starting the web into motion.

13. In combination, a web, a data recording device for said web, meansfor feeding said web across a predetermined space, a control mechanismhaving two positions, toggle means for maintaining said mechanism ineach set position until positively actuated to the other position, meansengaging said web 4intermediate said recording device and space foroperating said control mechanism to each position, said controlmechanism in one position serving to arrest the movement of the tape andin the other position to start the movement thereof.

14. In combination, a web, a data recording device for said web, meansfor feeding said web across a predetermined space, a control mechanismhaving two positions of operation, means controlled by the web betweenthe recording device and said space, when the web is reduced to apredetermined minimum length for actuating said mechanism to oneposition and when the web is increased to a predetermined greaterlength, to actuate said mechanism to the other position, means forretaining said control mechanism in each actuated position until saidweb has decreased or increased to a length suiicient

